Is GABA Really Useless? The Mysteries of GABA and the Intestines

On every little nootropic niche site out there, you can see articles like “Why GABA is useless.”

Well, they aren’t wrong in one sense: GABA does not readily cross the blood-brain barrier.

Variants on the GABA molecule phenibut and picamilon do cross the barrier, on the other hand, as do other agonists, and so GABA is passed up for these other forms. The actual neurotransmitter GABA taken as a supplement is therefore “useless” or inert to psychonauts who want a fast-acting head change.

Now is the ability to cross the blood-brain barrier a fair measure of a substance’s worth? I disagree.

Supplemental GABA may not be useless after all. The research might still be up in the air about this, but I have a few speculations (read: personal opinions/pet theories) as to how it may not be useless.

GABA and the Intestines

It’s possible that your “gut feeling” isn’t just a metaphor, it may very well be literal.

There is a lot more to the interplay between the sympathetic and parasympathetic nervous systems than we may know, as well as the role of the bacteria who reside in the intestines and all of the nutrients and neurotransmitters they produce there.

GABA receptors have been found not only in the brain but also in the nervous system that governs the gut, the enteric nervous system¹. It’s considered the “second brain” as it can operate autonomously, but communicates to the parasympathetic (via vagus nerve) and sympathetic nervous system (via prevertebral ganglia).

Yes, your intestines have their own GABA receptors.²

The implications may be fuzzy at first, but I have a gut feeling that GABA may play a bigger role in reducing anxiety and increasing calmness than we thought. I also believe that digestive disorders or anything that disturbs this “second brain” may be implicated in or associated with certain mental conditions such as autism.³

Alleviating these digestive issues could possibly, maybe rectify these conditions.

Should you take GABA to reduce anxiety?

Though this post is meant to vindicate supplemental GABA as being something far better than useless, it is not as psychoactive to the degree of phenibut or even L-theanine. So no, supplemental GABA taken orally cannot directly or immediately help with feelings of anxiety.

As stated before, GABA does not readily cross the blood brain barrier. Some GABA does eventually cross that barrier, but by dosage it is not psychoactive as other GABA receptor agonists, and will suppress its own ability to cross the barrier once it reaches a certain threshold⁴.

However… based on my understanding and guesswork, supplemental GABA may be useful for the gut or even take effect through the gut’s own enteric GABA receptors, which may explain why people still anecdotally find some benefit from taking GABA.

As the human intestines have GABA receptors of their own, and the gut is said to act as a sort of “second brain,” I do not think it is unreasonable that GABA can exert some benefits for mood disorders through this pathway.

Could Supplemental GABA Help The Digestive Tract?

A Chinese study published in 2014⁵ subjected two groups of one-day old male chickens to some form of heat stress that inhibited digestive function. They found that administration of a 0.2 mL GABA solution (50 mg/kg) to a second heat stressed group restored the digestive and immune function of intestinal mucosa.

Let’s read that again: Administration of a GABA solution restored digestive and immune function of intestinal mucosa.

By no means is one lone chicken study like this scientifically significant to us humans, but all signs here seem to point to something significant regarding supplemental GABA, and adds just a drop more to the mounting evidence about the influence of neurotransmitters on our guts and neurotransmitter-producing gut bacteria on our mood and overall health and well being.

There aren’t any more studies out there that I am aware of that support the use of supplemental GABA for these purposes, none of which I am aware of on humans. Thus, this is a job for self-experimenters until research catches up!

Can Supplemental GABA increase growth hormone secretion?

Quite a few people out there still take GABA due to its purported effects on growth hormone levels.⁶ Though there are apparently different kinds of growth hormone the body secretes and responds to, and whether or not this increased growth hormone is of any use or holds other implications unknown at this moment in time, it at least goes to show that GABA does something.

Conclusion

This entire post is speculative and should be taken with a grain of salt. My reasoning behind it is that if the digestive tract has GABA receptors and seems to absorb much of it, supplemental GABA taken orally may be useful after all for digestive health and an indirect mood benefit.

Considering how cheap GABA is (at Powder City, 100 grams for $4.56, 1 kilogram for $23) it’s easy to try this out for ourselves. There are few side effects from supplemental GABA aside from taking too high of a dose: flushing, nausea and shortness of breath.

I will begin to take GABA to see what it does for myself, alongside probiotics this year (a topic for a whole other post on its own). One factor in promoting healthy gut flora may be resistant starch, which I touched upon in the past.

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1. Wikipedia – Enteric nervous system ↩

2. GABA and GABA receptors in the gastrointestinal tract: from motility to inflammation — ScienceDirect ↩

3. New Insight into Autism and Intestinal Problems ↩

4. GABA and the Blood Brain Barrier – Examine.com ↩

5. Effect of γ-aminobutyric acid on digestive enzymes, absorption function, and immune function of intestinal mucosa in heat-stressed chicken – Oxford Journals – Poultry Science ↩

6. GABA and Growth Hormone — Examine.com ↩